American Megatrends MegaRAC M300V, User Manual

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58 MegaRAC® M300V Card Implementer’s Reference and User’s Guide
MCARD_DETECT_L = Logic High
When the MegaRAC M300V card is not present, the motherboard UART TXD and RXD signals
are routed to the motherboard’s serial connector. The X4 De-MUX direction is from Y to B.
X1
X2 X3
X4
X5
RS232 xlator
Connector
UART0 UART1
UART
BMC
CLI
Generator
ESC Snoop
BMC
Local Bus
Management
NIC
Super I/ O
Host System
Handshake Signals
UAR
T Handshake Signals
SoL / ESC Snoop
TxD, RxD
B not used when card installed
On-card TxD/ RxD
signal mux control
Handshake signal mux control
from mCard
Driven by UART but not felt at connector
TxD, RxD
TxD, RxD
Rx
A
B
Y
A
B
Y
A
B
Y
A
B
Y
A
B
Y
M300V Card
not Present